JPH0234864B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for winding a cross-wound thread, and more specifically, when winding a cross-wound thread, the yarn is broken while winding the cross-wound thread. The present invention relates to controlling the operation of a traverse guide that traverses between one traverse turning point and another traverse turning point.

The present invention can be carried out in general for winding cross-wound threads, but is particularly applicable to winding threads such as covering yarns, which have a relatively large fineness and whose core is covered with other threads. Suitable for taking.

The following will explain the covering yarn as an example.

[Conventional technology]

Covering yarn has a relatively large fineness, and the periphery of the core is covered with other threads, so that when winding a ribbon, even if it has not yet reached the state of ribbon winding, the adjacent threads on the winding body If they are close to each other, the loops of the surface yarns become entangled and the unwinding property is likely to be impaired.

In order to prevent such a decrease in unwinding performance, it is effective to prevent ribbon winding, and to prevent ribbon winding, it is effective to change the traversing length and break the edges.

However, the traverse device of a conventional crosswind device generally performs traverse by attaching a thread guide to a cam with a spiral groove and a cam follower guided by a guide groove that is linear in the spiral groove and in the axial direction. When breaking the selvedge using such a traverse device, the traverse length is changed by changing the inclination of the guide groove with respect to the axis of the bobbin using a cam member such as an eccentric cam. Although the shape of the circumferential surface of the cam can be arbitrarily designed, a cam profile that changes extremely rapidly cannot be adopted in consideration of the ability of the cam follower to follow the cam, the wear resistance of the cam and the cam follower, etc. For this reason, in the conventional method of breaking the edge of a cross-wound yarn body, the traverse width cannot be changed too rapidly.

In other words, when focusing on one end of the thread winding body, the turning point position of the traverse movement of the thread is determined by the outermost end position of the traverse turning point in the vicinity (of the maximum traverse width) in a certain double stroke (one reciprocation). It is not possible to move the object closer to the turning point position), move it away with the next double stroke, move it closer with the next double stroke, and move it further away with the next double stroke.

For this reason, in the conventional method of breaking the edges of a cross-wound thread, it is not possible to break the edges sufficiently, and it is not sufficient to prevent ribbons of the thread, prevent high edges at both ends, and prevent local hardness increases. There are some things that cannot be measured. Particularly in the case of a yarn such as a covering yarn in which the core portion is covered with another yarn, if adjacent yarns are located close to each other, the loops of the covered yarns tend to pinch each other. For this reason, it becomes difficult to unwind even if the ribbon has not yet reached the normal state of winding. Furthermore, since the yarn is bulky relative to its fineness, there is a problem in that selvage height is likely to occur.

In order to solve such problems, the present inventor first rotatably supported the yarn winding bobbin,
A method of connecting a traverse guide that traverses in the axial direction of the bobbin to a forward/reverse moving member via a traverse rod, and switching the direction of movement of the forward/reverse moving member to form a cross-wound thread body on the bobbin. In the traverse stroke vs. time diagram, the switching timing of the forward-reverse motion member is determined so that the virtual line connecting the turn points of the traverse motion of each end of the thread body on the traverse stroke vs. time diagram is a bend point at each turn point. He proposed a method for breaking the ends of cross-wound threads by changing the stent (Japanese Patent Application No. 1982-1902).

According to this method, the selvage can be sufficiently broken, and it is possible to sufficiently prevent the ribbon of the thread, the height of the selvage at both ends, and the local increase in hardness. In particular, even if the core is covered with other yarns such as covering yarns, it is possible to prevent adjacent yarns from being located close to each other, and prevent the covered yarns from pinching each other. It is possible to wind yarns with extremely large fineness without creating a selvage height.

When carrying out this method, by increasing the selvage width (i.e., the distance between the outermost position of the traverse turning point of the yarn and the innermost position of the traverse turning point), the ribbon prevention effect increases accordingly. Become.

[Problem that the invention seeks to solve]

However, if the selvage width is set to be large in order to sufficiently enhance the ribbon prevention effect, the amount of yarn winding at both ends of the thread body becomes too small, and the shoulders of the end faces become rounded, that is, the selvages droop, and this This causes the winding yarn to fall off the twill (a phenomenon in which it comes off from the selvedge).
Sometimes a problem arises. Furthermore, when the selvage width is increased, the winding tension of the yarn at the time of folding becomes low, which may cause a decrease in hardness or bulges at the end of the package selvage. As a result, the ease of unwinding the package is reduced, and it becomes meaningless to break the edges to prevent ribbons and improve the ease of unwinding.

In particular, for extremely stretchable yarns such as covering yarns, the winding tension is too low, and as time passes after winding, the selvage yarns shrink and move toward the center of the package cage width, causing the adjacent A problem may arise in which the threads overlap closely and get entangled, reducing unwinding performance. This phenomenon is more likely to occur as the time required for turning back is shortened.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for winding a cross-wound thread body without causing twill drop and preventing the formation of ribbons.

[Means for solving problems]

In the present invention, a yarn winding bobbin is rotatably supported, and a traverse guide that traverses in the axial direction of the bobbin is connected to a forward/reverse moving member via a traverse rod, and the forward/reverse moving member is moved. traverse direction, turn around one traverse turn-around point at zero traverse speed, rapidly accelerate to a predetermined traverse speed, head to the other traverse turn-around point at that traverse speed, and increase the traverse speed just before the other traverse turn-around point. In a crosswind winding method in which the traverse speed is rapidly decelerated and the traverse turning point on the opposite side is turned around at zero speed, at least the rate of change of the traverse speed is The winding method of the crosswind winding body is characterized by changing the winding once and breaking the ears by changing the positions of a plurality of traverse turning points in the traverse direction, so that the ears at both ends of the winding body hang down. This prevents the problem of the winding yarn falling off the twill.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below based on drawings illustrating embodiments of the present invention.

1 to 3 are schematic perspective views of a winding device implementing the present invention, respectively.

A friction roller 1 is connected to a drive source (not shown) to rotate at a constant speed, and a yarn winding bobbin 2 is brought into contact with and rotatably supported by the friction roller 1. A traverse guide 3 that traverses in the axial direction of the bobbin 2 is attached to a traverse rod 4.
is connected to reciprocal motion members such as an AC servo motor 5 (FIGS. 1 and 2), a DC servo motor, a stepping motor, and a hydraulic cylinder 6 (FIG. 3).

That is, in FIG. 1, a pair of traverse rods 4 are each supported so as to be able to reciprocate along a guide roll 7, and the pair of traverse rods 4 are connected to each other by a transmission member such as a timing belt 8. ing. The timing belt is stretched around pulleys 9, and a pulley 10 is provided coaxially with one of the pulleys 9, and a pulley 11 is attached to the output shaft of the AC servo motor 5. A transmission member such as a timing belt 12 is stretched between them. Thus, the traverse guide 3 can be traversed from side to side along the bobbin 2 by switching the rotational direction of the AC servo motor 5.

In FIG. 2, a pair of traverse rods 4
are connected to each other by brackets, and this bracket 13 is connected to another bracket 15 via a connecting rod 14.

The bracket 15 is suspended between a sliding block 17 movable along the guide rail 7 and a block 17 movable left and right along the screw shaft 18.
A transmission member such as a timing belt 12 is stretched between a pulley 19 attached to the end of the screw shaft 18 and a pulley 11 attached to the output shaft of the AC servo motor 5. Thus, by switching the rotation direction of the AC servo motor 5 and switching the rotation direction of the screw shaft 18, the traverse guide 3 can be traversed left and right along the bobbin 2.

In FIG. 3, the piston rod 6a of the hydraulic cylinder 6 is directly connected to the bracket 13 shown in FIG. By expanding and contracting the piston rod 6a of the hydraulic cylinder 6, the traverse guide 3 can be traversed from side to side along the bobbin 2.

In the apparatus shown in FIGS. 1 to 3, an imaginary line connecting the turning points of the traverse movement of each end of the thread on the traverse stroke vs. time diagram becomes a bending point at each turning point. As shown in the figure, the crosswind winding body is broken by changing the switching timing of the forward/reverse moving member.

It has been confirmed that the larger the selvedge width (that is, the distance between the outermost end position of the traverse turn-back point of the yarn and the innermost end position of the traverse turn-back point), the greater the ribbon prevention effect. However, when the selvedge breaking width is set large, the selvedges at both ends of the thread gradually droop, resulting in the problem of twill drop (a phenomenon in which the yarn comes off from the selvedges).

According to the inventor's study, the relationship between the selvedge width and the occurrence of twill drop varies depending on the brand of yarn to be wound, winding conditions, etc., but when the brand of yarn to be wound, winding conditions, etc. are constant. In this case, it was found that the rate of change in speed at the turning point of the traverse was the main influence.

This point will be explained below. In Figure 4, time is plotted on the horizontal axis and traverse speed is plotted on the vertical axis.
A traverse speed relationship diagram is shown.

The traverse speed line shown as a solid line in Fig. 4 turns around at the traverse turning point, rapidly accelerates to a predetermined traverse speed, heads to the other traverse turning point at the predetermined traverse speed, and then rapidly decelerates. Turn around at the traverse turning point.

On the other hand, in the traverse speed line indicated by a broken line, acceleration to a predetermined traverse speed and deceleration from the predetermined traverse speed are slower than in the speed line. Since the loss time during rise and fall is larger than that in the speed line of Setting up quickly.

FIG. 5 is a package position versus yarn winding amount diagram in which the horizontal axis represents the distance measured from one end surface of the package and the vertical axis represents the amount of yarn wound. The method for drawing the diagram in FIG. 5 based on FIG. 4 is roughly as follows.

If we take a certain time t in Fig. 4, the area surrounded by the horizontal axis and the traverse speed line with diagonal lines is the traverse distance l from the turning point of the traverse speed line to the time t, and the point of this distance l is Taken on the horizontal axis of Figure 5. Furthermore, since the yarn fed at a constant speed is traversed at time t in FIG. 4 at the speed represented by the corresponding traverse speed line,
A thread quantity is maintained on the package which is proportional to the reciprocal of the traverse velocity line. Below, by performing the same operation for each time and calculating the distance and yarn amount for the traverse speed line,
The diagram of FIG. 5 is obtained.

If the traverse width is constant and the yarn is traversed according to the traverse speed curves shown by the solid line and broken line in Figure 4, the traverse speed at the time of raising and lowering is slow, so the solid line in Figure 5 at the traverse turn-around section, respectively. , a peak height as shown by the broken line is formed. In other words, in the case of the traverse speed curve shown by the broken line, where the traverse speed near the turning point is slow, compared to the solid line,
Since many yarns are deposited near the traverse turning point, a large selvage height is formed.

Now, when the selvedge is broken as shown in Figure 6, the selvedge height curve shown in Figure 5 is drawn at each traverse turning point as shown in Figure 7, and it becomes a shape that is superimposed. , the selvage height of the traverse turning point shown in FIG. 5 is distributed within the selvedge area.

On the other hand, according to the inventor's experiments, in order to prevent twill drop when performing the above-mentioned selvedge breaking, it is necessary to form a certain minimum selvage height determined depending on the brand of the winding yarn, etc. It turned out that it would be a good idea to do so. The reason for this is considered by the inventor as follows. When you perform a selvedge, when viewed as a whole, the selvedge height curve is drawn at each traverse turning point and superimposed as described above, but at a certain moment, a certain selvedge height curve is drawn. In this case as well, a certain minimum selvedge height is required in order to prevent tread drop.

Assuming that the minimum required selvage heights to prevent tread drop are equal, the traverse speed curve shown by the broken line in Figure 4 has a large amount of selvage height as shown by the broken line in Fig. 5. It is possible to increase the selvedge width (that is, to distribute the selvage height over a wide range).
Therefore, by slowing the rise of the traverse speed as shown by the broken line in FIG. 4, it is possible to set a large selvage width without causing twill drop.

However, if the rise of the traverse speed is made too slow, the time period at which the traverse speed is low at the traverse turning point becomes longer, the winding tension of the system at this section becomes lower, and the difference in tension from the steady traverse section increases. As the winding tension increases, fluctuations in the winding tension become larger.

The decrease in tension at the traverse turn-back portion causes a decrease in the hardness of the edge of the package cage, and also causes a so-called bulge in which the rear yarn layer wound around the package cage shifts due to low tension and bulges out from the end surface of the package cage. The unwinding performance deteriorates, and it becomes meaningless to perform ear breaking to prevent ribbons and improve the unwinding performance. Particularly in yarns with many loops, such as covering yarns, adjacent yarns are very likely to get entangled with each other, and unwinding performance is poor when unwinding package cages where the hardness of the ears has decreased or bulges have occurred. .

In addition, the covering yarn has very high elasticity, and as shown in Fig. 11, the contraction force A of the yarn causes a force B directed toward the center of the package width to act on the yarn itself wound around the selvedge. As time passes after the threads are removed, the threads at the ends of the package move toward the center of the width of the package, causing adjacent threads to closely overlap and become entangled, reducing unwinding performance.

This change in the ears over time can be reduced by slowing down the traverse speed when starting and lowering the traverse, but on the other hand, as mentioned above, the decrease in hardness of the ears and the formation of bulges can have a negative impact on unwinding properties. appear.

The present invention has been made to solve such problems. In Fig. 8, which shows a time-traverse speed diagram, the solid line is the critical rising traverse speed line where no tension fluctuation occurs at the edge, and the broken line is the line where there is no twill drop and the edge height is sufficient to prevent ribbons. This is the rising traverse speed line. The dashed line is a diagram according to the method of the present invention.

The present invention reduces the rate of change of the traverse speed at least once during acceleration from zero traverse speed to a predetermined traverse speed. When the traverse speed becomes high enough that tension fluctuations do not become a problem, the rising speed is made slower than the traverse speed shown by the broken line, and the rising time is longer than that of . It should be about the height of the ears.

By winding the yarn along the traverse speed line shown in FIG. 8, the selvedge height shapes shown by solid lines and broken lines in FIG. 9 are obtained, respectively.

[Effect]

In the present invention, by moving on the solid rising line in FIG. 8 at the beginning of the start-up, winding can be performed without any tension fluctuation, and by making the selvedge height similar to that in FIG. 9, When the selvedge width is set to be the same when selvage is broken, the selvedge heights of the resulting package cages are approximately the same, and twill drop does not occur. In addition, the yarn locus at the edge end becomes gentler than in the case of , and the movement of the yarn over time after winding is reduced. Furthermore, according to the method of the present invention, the winding tension of the yarn at the time of rising does not become too low, and there is no decrease in hardness or bulges at the end of the package cage edge, and the winding tension of the yarn at the time of rising does not become too low. Even with large yarns, the yarns at the edges are not likely to shrink over time after winding, and adjacent yarns do not closely overlap and become entangled, resulting in good unwinding properties.

[Other aspects]

In the above description, the rate of change of the traverse speed is changed once, but it may be changed two or more times.

Although the above explanation has been made regarding the rise from the traverse turning point, the present invention can also be applied to the case where the traverse is falling toward the traverse turning point as shown by the chain line in FIG. 10. In this case,
During deceleration from a predetermined traverse speed to zero traverse speed, the rate of change of the traverse speed is increased at least once, particularly preferably a change in the traverse speed (dashed line) that provides a desired ear-breaking width from the predetermined traverse speed. The traverse speed is decelerated at a rate of change that is less than or equal to the rate of change, and then the rate of change is increased to a rate of change in the traverse speed (solid line) that does not substantially cause tension fluctuations in the ears of the thread.

Further, the above-described embodiments may be combined as appropriate, and further may be combined with other traverse speed lines.

〔Effect of the invention〕

According to the present invention, it is possible to wind up a cross-wound thread body without causing tension fluctuations or falling twills, and while preventing the occurrence of ribbons.

[Brief explanation of drawings]

1 to 3 are perspective views of an embodiment of a crosswind device for carrying out the method of breaking the edge of a crosswind thread according to the present invention, FIG. 4 is a time-traverse speed relationship diagram, and FIG. 5 is a package cage. A position-winding amount diagram, Fig. 6 is a selvage-breaking diagram, Fig. 7 is a diagram explaining how to draw an selvedge height diagram when selvage-breaking, and Fig. 8 is a time-traverse speed line of the present invention. Figure 9 is a package position-winding amount diagram according to Figure 8, Figure 10 is a time-traverse speed relationship diagram, and Figure 11 explains the contractile force acting on the yarn at the edge of the package. FIG. 2... Yarn winding bobbin, 3... Traverse guide, 4... Traverse rod, 5... Forward/reverse motion member.

Claims (1)

[Scope of Claims] 1. A traverse guide which rotatably supports a yarn winding bobbin and makes a traversing motion in the axial direction of the bobbin is connected to a forward/reverse motion member via a traverse rod, and the forward/reverse motion is Switch the direction of movement of the member, turn around one traverse turning point at zero traverse speed, rapidly accelerate to a predetermined traverse speed, head to the other traverse turning point at this traverse speed, and just before the other traverse turning point In a crosswind winding method in which the traverse speed is suddenly reduced at a traverse speed and the traverse turnaround point on the opposite side is turned around at zero speed, a change in traverse speed occurs during the change between zero traverse speed and a predetermined traverse speed. A method for winding a cross-wound yarn body, characterized in that the winding rate is changed at least once and the positions of a plurality of traverse turning points in the traverse direction are varied to perform the selvage breaking. 2. The method for winding a crosswind thread according to claim 1, wherein the rate of change in traverse speed is reduced at least once during acceleration from zero traverse speed to a predetermined traverse speed. 3 Accelerate from zero traverse speed at a rate of change in traverse speed that does not substantially cause tension fluctuations in the selvedge portion of the thread, and then reduce the rate of change in traverse speed to a rate of change that provides the desired selvage width. A method for winding a cross-wound thread body according to claim 2, which reduces the amount of winding. 4. The method for winding a crosswind thread according to claim 1, wherein the rate of change in traverse speed is increased at least once during deceleration from a predetermined traverse speed to zero traverse speed. 5 Decrease the traverse speed from the predetermined traverse speed at a rate of change in the traverse speed that is less than or equal to the rate of change in the traverse speed that provides the desired selvage width, and then reduce the traverse speed to a rate that does not substantially cause tension fluctuations in the selvage portion of the winding body. The method for winding a cross-wound thread body according to claim 4, wherein the rate of change is increased.